Youth in the child welfare system (CWS) are at very high risk for mental health problems and re-reports of maltreatment, and have greater mental health service needs compared to their peers.1,2 Parental characteristics such as depression, substance use, and parenting behaviors have been shown to predict child mental health and re-reports of maltreatment.3-7 However, the vast majority of this research has focused on mothers rather than fathers. Research on fathers' influences on youth in the CWS is needed to inform development of strategies to successfully engage fathers in intervention efforts. The proposed study will fill this major gap in the literature by identifying father-related risk factors for chid mental health and maltreatment using existing data from a longitudinal, national probability study of children and families investigated for child maltreatment (NSCAW-II). The specific aims of the study are to: (1) Describe the men who are primary in-home caregivers for children in the child welfare system and compare them to female in-home caregivers and men who are secondary caregivers; (2) Determine whether fathers' mental health and parenting predict child mental health outcomes and re-reports of maltreatment at 18 month follow up, and whether these associations differ by child age and gender; and (3) Compare fathers and a weighted sample of mothers on how parental risk factors (e.g., ineffective parenting, mental health problems) relate to child outcomes (mental health, maltreatment). Study findings will help to tailor existing prevention and intervention programs, which have been generally designed to target mothers, to better engage and address fathers who are caregivers for youth in the child welfare system. Given the high rates of medical and mental health problems of this population, these findings may have significant positive impacts on public health.